I recently updated my Nexus 9 to the nightly build of LineageOS 14.1 October 10. The normal update went smoothly. However, after rebooting, I was greeted with “A vendor mismatch has been detected. Typiucally this means yopur vendor image is out of date. Please ensure that your vendor image matches N9F27M”
According to Lineage, the nightlies are based on the October monthly updates from Google. Which means the vendor image needs to be extracted from the factory image from Google and updated on the Nexus 9.
Once the vendor img has been extracted or downloaded, you’ll need to use adb fastboot to install it.
- Connect to N9
- adb reboot bootloader
- fastboot devices
- fastboot vendor vendor-flounder-n9f27m.img
- fastboot reboot
N9 will reboot and you should no longer get that popup box